Tower-excavator.



C. G. OGLESBY.

TOWER EXCAVATOR.

APPLICATION FILED APR. a. 1916.

Patented Jan. 21, 1919.

- I STATES PANT OFFICE- CHARLES e. OGLESBY, or MEMPHIS, TENNESSEE,ASSIGNORY 'ro BUCYRUS COMPANY, 01 SOUTH MILWAUKEE, Wiscons n, ACORPORATION or WISCONSDT.

TOWER-EXCAVATOR.

Specification of Letters Patent.

Patented Jan. 21, 1919.

Application filed April 6, 1916. Serial No. 89,279.

To all whom it may concern:

Be it known that I, CHARLES G. OcLEsBY, a citizen of the United States,residing at Memphis, in the county of Shelby and State of Tennessee,have invented a certain new and useful Improvement in Tower-Excavators,of which the following is a specification.

My invention relates to improvements in tower excavating machineswherein a track cable is suspended between two towers and excavatormoved along the track cable as it performs the excavating, dumping andreturn movements. One object of' my invention is to provide a type oftower excavator wherein the parts may be light, simple and cheap inconstruction and operation. Another object is to provide a devicewherein the dirt may be easily and conveniently distributed andcompacted. Other objects of my invention will appear in thespecification. The invention is illustrated more or lessdiagrammatically in the accompanying drawing, wherein Figure 1 is a sideelevation of the machinery with the work in section;

Fig. 2 is a side elevation on an enlarged scale of the bucket in thedigging position; an

Fig. 3 is a detail showing the bucket in the hauling position.

Like parts are indicated by like letters throughout the several figures.

A is the dump. In the present instance it is the levee which is beingbuilt by deposition of the material which is taken by the excavator fromthe channel or cut A The head tower A stands on the bank beyond the dumpA. The tail tower A stands on the opposed bank on the other side of theexcavation A B is a trackcable anchored at B on the tail tower passingover a sheave B at the from the winding drum C over a sheave C at thetop of the tower A through the air to a return sheave C at the top ofthe tower A and thence to the trolley B being attached to the trolleyand thus a rotation of the drum C will tend to draw the trolley awayfrom the head tower toward the tail tower.

D is an excavating bucket. It is suspended from a trolley B by a singleline D attached to the lower portion of the bucket at the rear. D areguides on. the rear end of the bucket to guide the line D. D is adownwardly projecting ivot shoe or runner on the bottom of the buc et,located in front of the center of gravity of the bucket. D is the usualcutting edge and D a bail to which is attached the dra line D. This dragline passes over the s cave D on the tower A and is controlled by thewinding drum D in the usual manner. The winding drums are driven andcontrolled in any suitable way and for the sake of clearness and becausethe particular arrangement is not a part of my invention, I have omittedthe controlling means for driving the drums, this being in accordancewith the usual practice.

It will be evident that While I have shown in my drawings an operativedevice, still many changes might be made both in size, shape andarrangement of parts without departing from the spirit of my invention,and I wish, therefore, that my drawings be regarded as in a sensediagrammatic.

The use and operation of my invention are as follows The tWo towers arearranged one on either side of the excavation and dump. The trolley isfree to slide along the track cable. Starting with the parts in theposition shown in dotted lines, the operator will tighten up on thetrack cable raising the trolley and bucket away from the ground.

- The bucket will then be suspended in the position shown in full lines.The operator then starts the haul back cable meanwhile paying out thedrag line and the trolley is thus dragged back along the track until theexcavator bucket is at the excavatin point. The track cable is then paidout unti the bucket rests on the ground the track cable being hauledtight enough to rock the bucket about the curved shoe or runner so thatthe teeth or cutting lip is in engagement with the ground ready forcutting. The drag line is drawn in and the bucket is filled in the usualmanner. If the 'surface is irregular or inclined it may be necessary tomanipulate the track cable during the excavating movement and .this willbe done so that-the bucket will at all times The weight of the loadedbucket is never suspended by the track. The track cable has twofunctions. One of them to'tilt up the back .end of the bucket so thatexcavating can take place, the other to permit convenient return of thelight bucket to the excavating point. The bucket acts as an excavator, acarrier and as tamper and,

smoother, since as it is dragged along the SllI'ffiQQwWlt-h its loads ittamps and smooths off the previously excavated material.

The height of the tail tower does not need to be as great as the headtower but it must be great enough so that the track cable at the farside of the burrow pit or excavation be sufiicient to enable theoperator to tilt the bucketinto the digging position by raising it. i

The drag line and return line serve merely to move the bucket back andforth from the burrow pit to the dump. The manipulation of the trackcable controls the bucket to make itv perform all of the functions.

If the line is loose, the bucket slides along the ground withoutdigging. If tightened a little the bucket digs, or moves. cable .ishauled clear-up the bucket is emptied but at no time as above indicatedis the fully loaded bucket suspended on the track cable because theminute the dump commences the bucket begins unloading and before thebucket-is lifted off the ground a large portion will be discharged andas this operation occurs near to the head tower and the angles throughwhich these loads are applied are favorable. The towers may be light andeasily handled and constructed.

' The shoe, of course, serves as a combined I shoe and fulcrum and sinceit is in front of the center of gravity of'the bucket causes the bucketto tilt back insuring the freeing ofthe cutting lip from the ground.

It will be noted that the line for lifting the rear end of the bucket isattached to the bottom of the bucket at a point inside of the back andthe cable is carried around the back side of the bucket. The effect ofthis is that in all positions of the bucket there is a large moment armbetween the cen- If the ter of gravity of the bucket and the pullingdirection of this suspension chain. The

'promptness of the dump is directly proporthe hill as soon as the trackcable is tightened for the dump. Therefore,'it is necessary that thebucket be suspended as far back of the center of gravity as possible toget it to dump before it has run any considerable distance down thesloping track cable. M

It will be understood that the provision of the tail tower providesmeans for lifting the bucket clear of the ground at the ex-- tremeedgeof the burrow pit thus permitting the bucket to be lowered into thedigging position at the extreme back edge of the pit. The use of thistail tower also makes it possible to dump at any point in the embankmentand by changing the tension in the track cable this dumping position maybe controlled by cooperation with this tower in any suitable manner. Itwill be understood also that the tail tower gives the flexible anchorageas a contrast with the rigid anchorage thus saving any wear and tear onthe machinery and making it much more smooth in its operation.

The track cable in my invention, therefore,

has several functions. It serves in addition to transporting a bucket,as a hoisting cable,

a lowering cable, dumping cable and contions of the separate cablesusually used for these different purposes, thus by manipulation of thesingle cable the operator carries on the usual excavating processes inthe usual manner etting the same general result as would be 0 tained ifseparate lines were used.

I claim I 1. A drag line excavator comprising a drag bucket, a drag lineattached to the forward end thereof, means for drawing in the drag lineto move the bucket along the ground, a slack track line suspended abovethe bucket, means for varying the tension in the track line to raise andlower it, a

trolley movable along the track line, means when the bucket is in thecutting and dragging position, the upper end of the line bemg anchoredon thetrolley.

2. A drag line excavator comprlsing a trols the digging and performs allthe funcdrag bucket, a drag line attached to the fort rd end thereof,means for drawing in the drag line to move the bucket along the ground,a slack track line suspended above the bucket, means for varying thetension in the track line to raise and lower it, a trolley movable alongthe track line, curved guides extending upwardly along the rear wall ofthe bucket, and a lifting line anchored on the bucket at the lower endsof said guides 10 adapted to lie within the guides when the bucketis inthe cutting" and dragging posiin the presence of two witnesses,'this 1stday 15 of April, 1916.

CHARLES G. QGLESBY. Witnesses:

Roy H. MGKAY, F. R. GAGE.

